Legacy Documentation: Version 2017.2 (Go to current version)
LanguageEnglish
  • C#
  • JS

Script language

Select your preferred scripting language. All code snippets will be displayed in this language.

Application.lowMemory

Suggest a change

Success!

Thank you for helping us improve the quality of Unity Documentation. Although we cannot accept all submissions, we do read each suggested change from our users and will make updates where applicable.

Close

Submission failed

For some reason your suggested change could not be submitted. Please <a>try again</a> in a few minutes. And thank you for taking the time to help us improve the quality of Unity Documentation.

Close

Cancel

Description

This event occurs when an iOS, Android, or Tizen device notifies of low memory while the app is running in the foreground. You can release non-critical assets from memory (such as, textures or audio clips) in response to this in order to avoid the app being terminated. You can also load smaller versions of such assets. Furthermore, you should serialize any transient data to permanent storage to avoid data loss if the app is terminated.

This event corresponds to the following callbacks on the different platforms:
- iOS: [UIApplicationDelegate applicationDidReceiveMemoryWarning]
- Android: onLowMemory() and onTrimMemory(level == TRIM_MEMORY_RUNNING_CRITICAL)
- Tizen: ui_app_add_event_handler with type APP_EVENT_LOW_MEMORY

Here is an example of handling the callback:

#pragma strict
class LowMemoryTrigger extends MonoBehaviour {
    private function Start() {
        _textures = new List.<Texture2D>();
        Application.lowMemory += OnLowMemory;
    }
    private function Update() {
        // allocate textures until we run out of memory
        _textures.Add(new Texture2D(256, 256));
    }
    private function OnLowMemory() {
        // release all cached textures
        _textures = new List.<Texture2D>();
        Resources.UnloadUnusedAssets();
    }
}
using UnityEngine;
using System.Collections;
using System.Collections.Generic;

class LowMemoryTrigger : MonoBehaviour { List<Texture2D> _textures;

private void Start() { _textures = new List<Texture2D>(); Application.lowMemory += OnLowMemory; }

private void Update() { // allocate textures until we run out of memory _textures.Add(new Texture2D(256, 256)); }

private void OnLowMemory() { // release all cached textures _textures = new List<Texture2D>(); Resources.UnloadUnusedAssets(); } }

Did you find this page useful? Please give it a rating: